This invention relates to a guiding apparatus for an optical character reader. More particularly, the instant invention relates to an apparatus which supports an optical character reader and which guides it over a card containing information to be read by the optical character reader.
Optical character readers, sometimes called scanners, are commonly used for loading text from printed documents into computers. Optical character readers operate by causing them to pass over (scan) a region on a document or the like containing printed characters. The image of the characters is focussed by means of a lens onto an array of photoelectric transducers. A microprocessor inside the optical character reader recognizes the characters by comparing the light and dark portions of the scanned area with a reference matrix that is stored in a memory chip in the optical character reader.
Since each character must be individually scanned and recognized by the optical character reader, each character must be focussed onto the array of photoelectric transducers. In the past, this has necessitated that the optical character reader be physically repositioned along a line of print each time a character is to be read. Such positioning has proved to be a problem since most optical character readers are unable to recognize a character if it is inclined, even a slight amount with respect to the line of print that is being scanned. Since the scanning is usually performed manually, efficient scanning has in the past required an inordinate amount of patience and skill on the part of the operator.
U.S. Pat. No. 4,758,732 (Kyriakides) is an example of a prior art support and guiding apparatus for an optical character reader. The support and guiding apparatus disclosed therein includes a top frame, having a rail thereon. A hand-held optical character reader is mounted on the rail. A sheet of paper to be scanned by the optical character reader is inserted between a transparent top frame element and a bottom frame element which is spaced therefrom. The optical character reader slides along the rail scanning a line of text one character at a time. A window having tapered edges is provided in the top frame element through which an operator can insert a finger or thumb to advance the paper in a path transverse to the direction of movement of the optical character reader. In this way, the optical character reader does not become misaligned as it reads the characters on successive printed lines on the sheet.
The support and guiding apparatus in this prior art patent employs a transparent frame to hold the sheet being read in place so that the optical character reader can traverse the sheet. It also employs a frame having a single rail thereon which supports and guides the optical character reader for sliding movement so that it will be kept upright as the optical character reader scans across a line of text.
The support and guiding apparatus disclosed in this prior art patent is not entirely satisfactory. First, the use of a transparent frame to hold the sheet in place can lead to reflections reaching the optical character reader. Because of these reflections, the optical character reader may not correctly recognize the characters printed on the sheet being scanned. Second, because the optical character reader is mounted on a single rail, the optical character reader can twist to a certain extent as it is being moved along the rail, especially if it is pushed by one hand along one of its sides. This can cause the optical character reader to be slightly misaligned from a line being read. While the frame can be provided with two rails on which the optical character reader can be mounted in order to eliminate twisting, this can lead to difficulty in controlling the start and stop movements of the optical character reader. It may not be possible to fix the start and stop movements of the optical character as accurately as desired.
Furthermore, the apparatus disclosed in U.S. Pat. No. 4,758,732 is not well suited for scanning the information contained on an undersized document, for example, the information contained on a business card or an identification card. The apparatus disclosed therein is adapted for scanning full-sized documents which can be moved under the optical character reader via a fingerhole located at the edge of the top frame. Clearly, this apparatus would not work well for a small business card or identification card the edge of which does not reach the fingerhole.
Accordingly, it is an object of the present invention to provide a support and guiding apparatus for an optical character reader which does not suffer from the above deficiencies. In particular, it is an object of the present invention to provide a support and guiding apparatus for an optical character reader in which the information containing document is not placed underneath a transparent frame, and in which the start and stop movements of the optical character reader can be precisely controlled.
It is a further object of the present invention to provide a support and guiding apparatus which is well adapted for scanning information contained on an undersized document, such as a business card or an identification card.